Terahertz imaging with a direct detector based on superconducting tunnel junctions

Abstract

We demonstrated terahertz imaging using a direct detector based on niobiumsuperconducting tunnel junctions(STJs). The detector is composed of linearly distributed junctions placed on a superconducting microstrip line and is integrated on two wings of a log-periodic antenna. We succeeded nondestructive imaging for an integrated-circuit card and dry material using the detector around its sensitivity peak ( ∼ 0.66 THz ) . The dynamic range was measured to be higher than 4 × 10 7 ( 76 dB ) . Thus, the STJdetector is applicable to high-sensitivity and high-speed terahertz imaging for various nondestructive inspection applications.